1. Field of the Invention
The present invention relates to a rotor, and more particularly to a rotor of a synchronous motor.
2. Description of the Prior Art
Typical rotors are rotatably provided in a stator or are rotatably engaged on a stator of a synchronous motor. U.S. Pat. No. 4,631,807 to Kawada et al, U.S. Pat. No. 5,010,266 to Uchida, U.S. Pat. No. 5,140,211 to Ucida, U.S. Pat. No. 5,157,297 to Uchida, and U.S. Pat. No. 5,463,262 to Uchida disclose several arts of the rotor, and include a number of laminated core members arranged around a rotating shaft, and a number of permanent magnets radially arranged around the rotating shaft and engaged in the laminated core members. The laminated core members are secured together by two end plates and by six or more screw fasteners which include the ends that are extended outward through the laminated core members and the end plates. The ends of the fasteners that are extended outward through the end plates may affect the operation of the rotor. In addition, it takes a long time to thread and to secure the screw fasteners together. Furthermore, the laminated core members of some of the synchronous motor are separated from each other and are required to be assembled together during the assembling operation. The precisions of the outer peripheral portions of the laminated core members thus may not be easily controlled.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional rotors.
The primary objective of the present invention is to provide a rotor of a synchronous motor having a number of laminated core members secured together by fasteners that are not extended outward through the end plates.
In accordance with one aspect of the invention, there is provided a rotor for a synchronous motor comprising a shaft including a first end portion having a peripheral shoulder provided thereon and including a second end portion, a first end plate engaged on the shaft and engaged with the peripheral shoulder of the shaft, the first end plate including an inner surface having a plurality of ribs extended therefrom, a plurality of laminated core members engaged on the shaft and engaged with the inner surface of the first end plate, the laminated core members including a plurality of radially arranged apertures formed therein for receiving the ribs of the first end plate, a plurality of permanent magnets received in the apertures of the laminated core members, and including a first end engaged with the ribs of the first end plate, and including a second end extended outward of the laminated core members. a second end plate engaged on the shaft and engaged with the laminated core members, the second end plate including an inner surface having a plurality of cavities formed therein for receiving the second end of the laminated core members, the second end plate including an outer portion, and a fastener engaged onto the second end portion of the shaft and engaged with the outer portion of the second end plate for securing the first end plate and the second end plate and the laminated core members on the shaft. The end plates and the laminated core members may be easily and quickly engaged onto the shaft and may be easily and quickly secured on the shaft with the single fastener.
A securing device is further provided for securing the second end plate to the shaft and includes at least one key engaged between the second end plate and the shaft for securing the second end plate to the shaft and for preventing the second end plate from rotating relative to the shaft. The second end portion of the shaft includes an outer thread formed thereon and threaded with the fastener for allowing the end plates and the laminated core members to be easily and quickly secured on the shaft with the single fastener.
The shaft includes at least one annular recess formed therein, the laminated core members include slot formed therein and defined by at least two coupling elements. the slot of the laminated core members is aligned with the annular recess of the shaft.
Further objectives and advantages of the present invention will become apparent from a careful reading of a detailed description provided hereinbelow, with appropriate reference to accompanying drawings.